These days, instruments that perform a surgical operation by using ultrasonic waves have been gradually developed. A representative tool for surgical operation used in laparoscopic surgery among them is Harmonic Scalpel disclosed in Japanese Patent No. 4307890.
However, in the case of the Harmonic Scalpel in the related art, which is disclosed in Japanese Patent No. 4307890, a maximum value which a gain step can have in order to ensure a maximum active length cannot be ensured, and as a result, ultrasonic wave strength cannot be maximized.
That is, in the tool for surgical operation using the ultrasonic waves, such as the Harmonic Scalpel in the related art, the active length and the gain step are determined as contrary components, and as a result, only an instrument performing the surgical operation, which can perform cutting and hemostasis by selecting only any one of both components according to a surgical site has been developed.